Packaging machine



PACKAG ING MACHINE Fild Feb. 5. 1964 5 Sheets-Sheet 1 FIG. 1

Nov. 7, 1967 A. GRAFINGHOLT ET AL- 3,350,840

PACKAGING MACHINE Filed Feb. s. 1964 s Shets-Sheet 2 FIG. 2

NGV. 7, 1967 GRAHNGHQLT ET AL 3,350,840

PACKAGING MACHINE Filed Feb 3, 1964 3 Sheets-Sheet 5 FIG. 4

FIG 5 United States Patent Office 3,350,840 Patented Nov. 7, 167

3,350,840 PACKAGING MACHINE Alfred Griifingholt, Stuttgart-BadCannstatt, and Rudolf Branstuer, Fellbach, Wurttemberg, Germany,assignors to Fr. Hesser Maschinenfabrik-Aktiengesellschaft,Stuttgart-Bad Cannstatt, Germany, a corporation of Germany Filed Feb. 3,1%4, Ser. No. 341,955

Claims priority, application Germany, Feb. 18, 1963,

3 Claims. (Cl. 53180) This invention relates to an apparatus, used inpackaging machines, by means of which a printed web of packagingmaterial, or a tube which has been formed around a shaping mandrel froma printed web of packaging material, is drawn forward intermittently bya web-drawing means under the action of an oscillatory systern which iscoupled to the web-drawing means and re ciprocates these meansperiodically between two end positions, the position of the imprintrelativeto the package to be produced being controlled by means of aregistration-regulating means.

In a known machine for producing bag packages, a tube formed around ashaping mandrel from a printed web is drawn forward by a pair ofclamping and sealing jaws which are moved intermittently up and downthrough one bag length per stroke. To guarantee the registra-tionbetween the imprints and packages, the drawn length, that is the strokeof the clamping and sealing jaws, is set to be slightly more than thespacing between the imprints on the web. The deliberate faults therebyinduced in the registration are to be corrected, when they reach apredetermined size, under the supervision of a photocell, thet sealingjaws being opened by this cell during the drawing down of the tube andshortly before they reach their lower end position so that the tube isonly drawn down through one bag length less approximately the size ofthe error.

Although the aim is to restore correct registration between the bagpackages and its imprint, it is found impossible in practice to obtainexact maintenance of registration between the bag and its imprint inthis way because it involves an abrupt release of the infed tube ofpackaging material, which is in motion and into the lower part of whichfilling material has been introduced with a free fall. Because of itsmomentum the tube comes to a standstill at an indeterminate instantwhich is sooner or later depending on the frictional conditionsprevailing between the inside of the tube and the shaping mandrel and itbecomes impossible to guarantee exact regulation of the registration.

To circumvent this defect, in accordance with the pres ent invention itis proposed that the effective stroke of the draw means produced by theoscillatory system be adjustable in such a way that, in the event of aregistration fault exceeding a predetermined amount, at least one of thetwo end positions of the draw means is displaced by means of theregistration-regul ating means. This produces a situation in which thetube is permanently under control during its forward movement, and thelength drawn off can be optionally increased or reduced.

In a preferred embodiment of the invention the oscillatory system isconnected to the draw means through a draw bar and an eccentricallyadjustable coupling for controlling the stroke of this draw means. Bythis arrangement the point of engagement of the draw bar with the drawmeans is displaced when the coupling is adjusted.

The invention is described hereafter with reference to severalembodiments illustrated in the attached drawing.

In the drawing:

FIGURE 1 shows a first embodiment of a packaging machine in front view,partly in section,

FIGURE 2 shows the driving mechanism of the machine in FIGURE 1,separately and in a further operating position,

FIGURE 3 is a wiring diagram for a device for regulatin registration inthe machine,

FIGURE 4 is a front view of the draw means of a further embodiment, and

FIGURE 5 a plan view of the draw means of FIG- URE 4.

In the embodiment of the invention illustrated in FIG. 1, bag packages-]3 are fabricated from two heat scalable webs C and D, of which atleast web C is printed. Both webs C and D are first folded into the formof a tube around a hollow vertical shaping mandrel 1, in a manner whichis known per se and will not therefore be further explained, and thenconnected together by means of heat sealing jaws 2 and 3. The fillingmaterial is charged through the hollow shaping mandrel 1 into the lowerend of the tube, which is closed by a transverse seam formed by a pairof heated clamping jaws 4 and 5. The clamping jaws 4 and 5, which arereciprocable between two end positions, are also used to draw the tubeforward each time by a bag length and to transversely separate and forma top seal at the upper tube end of each filled bag package B.

The conversion of the transverse movements into the transverseseparating and sealing of the tube is performed by securing the clampingjaws 4 and 5 to arms 6 which, in conjunction with levers 8, 9 pivoted toa carrier 7, provide .a parallelogram linkage. The transverse movementof the clamping jaws 4 and 5 is efiected by bars 10 which arereciprocated in timed fashion in known manner as for example shown inapplicants prior US. Patent 3,091,902 and impart movement to the arms 6.

The forward draw of the tube with the clamping jaws 4, 5 closed, iseffected by moving the carrier 7, the levers 8, 9 and arms 6 downwards.For this purpose the carrier 7 is firmly attached to a vertically guidedbar 12 having a draw link 14 pivotally connected to its lower end 13.The other end of this draw link 14- is pivotally connected to a rocker15' which is pivoted about a fixed pivot point and is coupled by a link16 and a tie 17, to a crank 18. To ensure that there is a pause in themovement of the clamping jaws 4 and 5 when they are in their upper andlower end position-s, with the crank 18 turning uniformly, the tie 17 isequipped with a roller 19' guided in a kidneyshaped guide groove 20 in afixed cam plate 21.

To allow for setting the tube for forward movement through apredetermined length of travel corresponding to a required bag length,the rocker 15 has a longitudinal slot 22 in which is adjustably engageda block 24 articulated to the draw link it, thus enabling the length ofthe eifective lever arm of the rocker 15 to be varied. This slot 22 isof arcuate shape so thatthe upper dead center of the clamping jaws 4, 5will invariably be in the same place when there is a change in bagformat.

In the present embodiment the stroke of the draw link 14, and that ofthe carrier '7 and clamping jaws 4, 5 are set a little more than thetheoretical distance from imprint to imprint on the tube formed fromwebs C and D. When the predetermined sizing error occasioned thereby isdetected by a photocell 25 associated with the shaping mandrel 1, theupper end position of the clamping jaws 4 and 5 is offset downwards by aspecific amount corresponding to this error.

For this purpose (see FIGURES 1 and 2) the draw link 14 is pivoted to aneccentric pin 26 on a stud 27 which is rotatably mounted in the lowerend 13 of the bar 12. This stud 27, which is comparable to a crank, hasat its other end a lever 28 (see FIGURE 2) which 38 carries a roller 29engaged in the slideway of a rockable bar 30. Rocking of the bar 30about the pivot 30 through lever 28 turns the stud 27, through apredetermined angle so that the eccentric axis of the pin 26, which isnormally located in a horizontal plane with the axis of the stud 27, isnow set higher than the axis of the stud. This reduces the actualdistance between the rocker 15 and the bar 12 so that the upper endposition of the clamping jaws 4, is displaced downwards a predetermineddistance. During the subsequent forward draw of the tube the returnpivoting of the bar 30 increases the distance between the member 15 andthe bar 12 to the normal value again, so that the clamping jaws 4, 5will now execute a smaller distance of forward travel than normal, and ashorter bag length will be advanced.

To implement a registration correction by this means, the bar isconnected through a link 31 with a lever arm 32 having a bell cranklevel 33 mounted on the pivot axis 32' thereof, this lever 33 beingrocked in timed fashion by a cam 34 which turns continuously at the sameangular speed as the crank 18. The lever arm 32 is coupled to the bellcrank lever 33 when the photocell 25 emits a signal for correction ofthe registration. To this end the lever arm 32 has a rockable lever 35with a pin 36 and a roller 37. The roller 37 is applied against apivotable arm 38 which is coupled through levers 39 and 40 with thearmature of an electromagnet 41 (FIGURES 1 and 2). When theelectromagnet 41, as disclosed in more detail hereinafter, is energizedby the photocell 25, the arm 38 turns the lever 35 so that the pin 36 ofthe latter engages in the forked free end of the bell crank lever 33. Asa result of this positive coupling, the lever arm 32 is obliged toperform a pivotal motion along with the bell crank lever 33 and this istransmitted to the bar 30.

To provide for a predetermined amplitude of correction, the lever arm 32has a longitudinal slot 43 in which the link 31 can be attached inarticulated fashion at a desired location.

To provide for maintainence of the registration, the imprint on the tubeis scanned by the photocell 25 in known fashion each time during a pausein the travel. To arrange for this, a switch contact 46 is provided inthe circuit of the photocell 25 (FIGURE 3) and is periodically closed bya rotating cam 47. The impulse produced by the photocell 25 in responseto an error in the registration is amplified in an amplifier 48 andpassed to the electromagnet 41 so as to energize it.

Additionally it is to be noted that, for correction of errors in theregistration, the oscillatory system for effecting the forward draw onthe tube can of course be such that the correction increment of travelis more than the normal stroke. This arrangement will be used if thenormal distance of the forward draw is set less than the distancebetween imprints.

Moreover the oscillatory system can be constructed in simple fashion sothat the lower end position of the travel of the clamping jaws is ofisetto correct faulty registration.

Whereas, clamping jaws 4 and 5 are provided to draw the tube in theembodiment illustrated in FIGURES 1 and 2, and also to serve as sealingjaws for forming the transverse seams, in the embodiment of FIGURES 4and 5 two separate devices are used for this purpose, namely, sealingjaws 5t 51 and additional clamping jaws 52, 53 and blocks 54 whichco-act with the latter. All these parts are supported by the carrier 7which is rigidly connected to the bar 12 through a web 66.

This embodiment provides for the formation of a tube with corner ribs K.To enable the draw means to engage the corner ribs K the jaws 52, 53 arearranged for transverse movement relatively to the tube, while theblocks 54, which serve as a counter support, are connected to stays 55which are firmly connected to the carrier 7, so that each lies betweentwo ribs K of the tube. The clamping jaws 52, 53 are secured to U-shapedarms 59 which, together with the levers 56, 57 and the carrier 7 formparallel linkages. To impart a transverse movement to the clamping jaws52, 53, use is made of bars 58 Which reciprocate in timed fashion andagainst which run rollers 67 on the arms 59.

In a similar way, the transversely movable sealing jaws 50, '51 aresecured to arms 60 which constitute a parallelogram linkage with levers61, 62 and carrier 7. Bars 63, against which run rollers 64 on arms 60,control the formation of the transverse seam through the medium of areciprocatory motion of the sealing jaws 50, 51, independently of theclamping movement described. The levers 56, 57 and 61, 62, to which thearms 59 and 60 for the clamping and sealing jaws are pivotally connectedare rockably mounted on four spindles 65 secured in the frameworkcarrier 7.

In the last-described embodiment the register-retaining forward draw onthe tube is ensured in very effective fashion because the separateclamping jaws, together with the small blocks, preselect the bottom ofthe bag packages in unequivoca'ble fashion.

The apparatus according to the invention can be directly used for otherkinds of packaging machine in Which there is the requirement for anexact maintenance of registration in the forward draw of a web ofpackaging material.

We claim:

1. In a packaging machine, draw means for engaging packaging material,an oscillatory system coupled to said draw means to reciprocally movethe same between end positions to advance said material, saidoscillatory system including a draw bar pivotally connected to said drawmeans, a pivotal rocker member connected to said draw bar and drivingmeans for pivotally moving said rocker member, aneccentrically-adjustable coupling between said draw bar and said drawmeans for modifying their point of connection and adjustable regulatingmeans for acting on said coupling for varying at least one of the endpositions of said draw means, said coupling comprising a rotatablemember in said draw means, and an eccentric pin on the rotatable member,said draw bar being pivotally mounted on the eccentric pin to change theend positions of the draw means when the rotatable member is rotated inthe draw means.

2. A machine as claimed in claim 1 wherein said regulating meansincludes a pivotal adjusting bar coupled to the rotatable member forrotating the same, adjusting means for acting on said bar and materialscanning means coupled to the latter means for pivotally moving saidbar.

3. A machine as claimed in claim 2 in which the adjusting meanscomprises a guide bar connected to said adjusting bar and rockable topivot the latter, and a lever and linkage system operable by saidscanning means to actuate said guide bar.

References Cited UNITED STATES PATENTS 2,483,155 9/1949 Salfisberg 53512,815,620 12/1957 Prodigo 53-480 X 2,826,021 3/1958 Van Den Berg et al.5351 2,950,588 8/1960 Gausman 5351 3,055,154 9/1962 Markley et al. 5351X 3,091,902 6/1963 Reinhardt et al. 53180 X 3,159,955 12/1964 Thurlings53-180 3,188,781 6/1965 Aquarius 53-18O GRANVILLE Y. CUSTER, ]R.,Primary Examiner.

1. IN A PACKAGING MACHINE, DRAW MEANS FOR ENGAGING PACKAGING MATERIAL,AN OSCILLATORY SYSTEM COUPLED TO SAID DRAW MEANS TO RECIPROCALLY MOVETHE SAME BETWEEN END POSITIONS TO ADVANCE SAID MATERIAL, SAIDOSCILLATORY SYSTEM INCLUDING A DRAW BAR PIVOTALLY CONNECTED TO SAID DRAWMEANS, A PIVOTAL ROCKER MEMBER CONNECTED TO SAID DRAW BAR AND DRIVINGMEANS FOR PIVOTALLY MOVING SAID ROCKER MEMBER, ANECCENTRICALLY-ADJUSTABLE COUPLING BETWEEN SAID DRAW BAR AND SAID DRAWMEANS FOR MODIFYING THEIR POINT OF CONNECTION AND ADJUSTABLE REGULATINGMEANS FOR ACTING ON SAID COUPLING FOR VARYING AT LEAST ONE OF THE ENDPOSITIONS OF SAID DRAW MEANS, SAID COUPLING COMPRISING A ROTATABLEMEMBER IN SAID DRAW MEANS, AND AN ECCENTRIC PIN ON THE ROTATABLE MEMBER,SAID DRAW BAR BEING PIVOTALLY MOUNTED ON THE ECCENTRIC PIN TO CHANGE THEEND POSITIONS OF THE DRAW MEANS WHEN THE ROTATABLE MEMBER IS ROTATED INTHE DRAW MEANS.